Gm Brembo upgrade added...sluggish acceleration and much lower mpg.

[Doubeleive]

Yes, sprung vs unsprung weight. Rotational vs static. https://www.linkedin.com/pulse/what-sprung-unsprung-weight-nikhil-jagdale#:~:text=Sprung weight includes anything supported,you're considering making modifications

It will be interesting to see what it ends up being. Hopefully he replies back with a quick fix.

Ok so then by your theory I should be able to downgrade my brakes to the old 13" and get the cheapest lightest pads I can find and some old aluminum Silverado wheels (light as hell) and some lightweight tires and gain 6-8mpg? Right, ain't gonna happen

 

[Doubeleive]

And how come when I went from 16" wheels to 22" wheels chrome and heavy I didn't go oh sh$t where did my mpg go? Because the effect is not that great on these big heavy bastard trucks, ya you might be able to see it in controlled conditions but it's not going to be much.

 

[Rocket Man]

Dude doesn’t know when to give up.
You know, he’s smarter than the rest of us…

 

[Rocket Man]

No one is blowing smoke. I showed you the link that goes in detail what rotational mass can do. It may not be a result of his total 8mpg decrease but it is no doubt attributing to it. Especially if he is pressing the gas more to overcome the heavier feel. Im willing to bet the truck feels 'heavier' to him and he is using the gas to compensate.

Rotational mass increase can make a vehicle feel very labored. Some less sensitive may not feel it. But many people will.

It could be a dragging brake but he mentions no heat. A single caliper dragging will also cause a pull. What's the likelie hood of a pair dragging ? Probably pretty slim. So next up would be a e brake dragging. Again he says no heat. So that may or may not be it. He doesn't mention any pulling so that rules out a single corner.

The one fact we do have is that he put giant brakes on his suv and complains that it is labored and struggling and low mpg.

To rule out what im saying as 'smoke' is ignorant.

You’re something. You’ve now called me ignorant, after first calling me stupid as in “It's basic physics. Heres a quick simple read to help you over come your lack of understanding” and so on. You’re wrong, again, if you think a BBK is contributing to a decrease in mpg by anything noticeable. AGAIN, I say prove it happens on a full size GM SUV. Let’s see your evidence. Not that article, real actual user experience where the mpg decreased due to installing a BBK on a FULL SIZE GM SUV which is what we are talking about.

 

[randeez]

sub'd

cause this keeps getting better and better

 

[George B]

sub'd

cause this keeps getting better and better

Right?!

 

[randeez]

You’re something. You’ve now called me ignorant, after first calling me stupid as in “It's basic physics. Heres a quick simple read to help you over come your lack of understanding” and so on. You’re wrong, again, if you think a BBK is contributing to a decrease in mpg by anything noticeable. AGAIN, I say prove it happens on a full size GM SUV. Let’s see your evidence. Not that article, real actual user experience where the mpg decreased due to installing a BBK on a FULL SIZE GM SUV which is what we are talking about.

i dont know man....when i fill my yukon up with gas my mpg goes down pretty quick. when its nearly out i get a lot better mpg. explain that genius, clearly its the extra weight of fuel

 

[Rocket Man]

i dont know man....when i fill my yukon up with gas my mpg goes down pretty quick. when its nearly out i get a lot better mpg. explain that genius, clearly its the extra weight of fuel

It’s basic physics. Need a link?

 

[Thrust]

Yes, sprung vs unsprung weight. Rotational vs static. https://www.linkedin.com/pulse/what-sprung-unsprung-weight-nikhil-jagdale#:~:text=Sprung weight includes anything supported,you're considering making modifications

It will be interesting to see what it ends up being. Hopefully he replies back with a quick fix.

I love when people link to articles that have ZERO equations or test data backing up what they say. Yes agreed, it's always better to reduce unsprung weight but since I don't see anything in the OPs post of how much the stock setup compared to the Brembo setup it's hard to say what that difference is. And coming from someone who did the Brembo brake upgrade myself, I didn't notice a change in MPGs, but when you have a supercharger on top of your engine you don't really care about MPGs.

 

[DuraYuk]

Loaded down vehicles getting the same mpg!? Heavier bigger wheels and tires getting same mpg!? Yeah we are at a crossroads here. Im gonna head out now and curiously await whatever OP finds. I put my 2 cents in as a former GM heavy line tech and current mech engineer. Was just trying to help and combat some misinformation.

Maybe my tone was misread. Idk. Hope everyone is having a good day.

Smh.